XI: s-block Flashcards
What is polarising power?
[Ionic charge]/[(ionic radius)^2]
Which alkali metal ion has highest hydration energy?
Li
What is the colour of the flame that Lithium imparts to Bunsen burner?
Red
What is the colour of the flame that Sodium imparts to Bunsen burner?
Golden yellow
What is the colour of the flame that potassium imparts to Bunsen burner?
Pale violet
What is the colour of the flame that Rubidium imparts to Bunsen burner?
Reddish violet
What is the colour of the flame that Cesium imparts to Bunsen burner?
Sky blue
Which is the lightest metal?
Lithium
Density decreases along the period. True/false?
False. It increases along a period
Melting point decreases down the group. True/false?
True
Which is more reactive- lithium or cesium?
Cesium
The compound forms of alkali metals are diamagnetic. True
True
Does the stability of alkali hydrides decrease down the group?
Yes
NaH + H2O ————->
NaOh + H2
Na2O2 + H2O ————–>
NaOH + H2O2
KO2+H2O————>
KOH + H2O2 + O2
Which alkali halide is not freely soluble in water?
Lithium fluoride
Why does caesium iodide have low solubility in water?
Because of the small hydration energy
Is blue coloured solution of alkali metal in ammonia paramagnetic ?
Yes
Is brown coloured solution of alkali metal in ammonia paramagnetic ?
No. Its diamagnetic.
How does the complex forming power vary in first group?
Li> Na> K> Rb> Cs
Lithium is softer and has a lower melting point than other alkali metals. True/false?
False. Lithium is harder and has a melting point than other alkali metals.
Lithium can form hydrates but other alkali metals cannot form hydrates. True/false?
True
LiOH on heating gives
Li2O + water
LiNO3 on heating gives
Li2O +NO2 + O2
KNO3 on heating gives
KNO2 + O2